VmTerminalApp: Show error activity for unrecoverable error

This CL launches error activity for any of followings:
  - Uncaught exception
  - Failed to connect to VM due to the timeout
  - Failed to create client certs
  - Failed to start VM

To achieve so, error activity is changed to be run on the separated
process because main process may be shutting down.

Bug: 381182508
Bug: 376796062
Test: Manually with KEYCODE_UNKNOWN, plus wrote local patch to throw \
   exceptions from activity, service, and executor service.
Change-Id: I610136a181109a0d1bd5cb996f5c81873fcb6824
diff --git a/android/TerminalApp/AndroidManifest.xml b/android/TerminalApp/AndroidManifest.xml
index 7dab58d..726004c 100644
--- a/android/TerminalApp/AndroidManifest.xml
+++ b/android/TerminalApp/AndroidManifest.xml
@@ -54,7 +54,9 @@
             android:label="@string/settings_port_forwarding_title" />
         <activity android:name=".SettingsRecoveryActivity"
             android:label="@string/settings_recovery_title" />
-        <activity android:name=".ErrorActivity" />
+        <activity android:name=".ErrorActivity"
+            android:label="@string/error_title"
+            android:process=":error" />
         <property
             android:name="android.window.PROPERTY_ACTIVITY_EMBEDDING_SPLITS_ENABLED"
             android:value="true" />